Thanks for the headlamp tip. Mine just arrived and I'm very pleased! The light seemed plenty bright in my outdoor test just now. And the weight with battery should be exactly an ounce once I cut the B.D. label off. :-) I did notice the light bouncing a little when I was walking due to the narrow base against the forehead. But for sitting around camp it will be perfect.

You might be able to waterproof it by using some silicone caulk from the hardware store. Just apply it anywhere the water can intrude and you can peel it off when you need to change batteries. I used the caulk to waterproof a homemade headlamp a couple of years ago. Worked well.